<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>过渡</title>
  <style>
    .box1 {
      width: 200px;
      height: 200px;
      background-color: orange;
      /* 设置哪个属性需要过渡效果 */
      transition-property: width, height;
      /* 设置过渡的时间 */
      transition-duration: 1s, 5s;
      /* 过渡延迟 */
      transition-delay: 2s;
      /* 过渡类型 */
      transition-timing-function: ease;
      /* 复合属性 */
      /* transition: 1s 2s ease width; */
    }
    .box1:hover {
      width: 400px;
      height: 400px;
    }
  </style>
</head>
<body>
  <div class="box1"></div>
</body>
</html>